Metal oxide semiconductor (MOS) power transistor devices have gained popularity in certain applications for their high power capabilities. There are various types of MOS power transistor devices, including diffused metal oxide semiconductor (DMOS) devices, such as Lateral DMOS (LDMOS) devices, vertical DMOS devices and trench DMOS devices.
For proper operation of a power transistor device, e.g., a DMOS device, an appropriate amount of thermal coupling should exist between the current carrying channel and the metal heat sink upon which the device is mounted. Reflow mounting is a common process used to mount a power transistor device on a metal heat sink. During reflow mounting, the power transistor device is soldered to the metal heat sink.
Heat removal is important for proper operation of these power transistor devices. Typically, efforts are made during the processing of power transistor devices to ensure that proper thermal coupling between the device and the metal heat sink is possible so that sufficient heat removal upon mounting of the devices is attained. However, there exists a need for power transistor processing techniques that provide for improved thermal coupling and thus maximal heat removal.